Armored Corvette design, 1874
Friends have informed me that this design appears to be for a minor variant of the Sachsen class ships, and would have been the 5th unit of that class (likely named Oldenburg). However, the ship was never built though a cheaper unit was built a few years later and given the name Oldenburg.
If you have more information on this drawing, please contact me via the link at the top of the page.
Peter Klein offers the view that
[This] is simply the first ship of the Bayern-class from 1874, the Bayern, as you can see in the lower right corner (Bayern Blatt 5 => sheet 5).I'll look into that and amend this page.